Datasheet

ADP1610
Rev. A | Page 16 of 20
SEPIC POWER SUPPLY
The circuit in Figure 30 shows the ADP1610 in a single-ended
primary inductance converter (SEPIC) topology. This topology
is useful for an unregulated input voltage, such as a battery-
powered application in which the input voltage can vary between
2.7 V to 5 V, and the regulated output voltage falls within the input
voltage range.
The input and the output are dc-isolated by a coupling capacitor
(C1). In steady state, the average voltage of C1 is the input voltage.
When the ADP1610 switch turns on and the diode turns off, the
input voltage provides energy to L1, and C1 provides energy to
L2. When the ADP1610 switch turns off and the diode turns on,
the energy in L1 and L2 is released to charge the output capacitor
(C
OUT
) and the coupling capacitor (C1) and to supply current to
the load.
2.5V–5.5V 3.3V
IN
SD
SS
RT
SW
ON
FB
COMP
C
SS
22nF
GND
L1
4.7µH
4.7µH
L2
ADP1610
56
3
2
7
8 1
4
C
IN
10µF
C
COMP
1nF
R
COMP
60kΩ
C
OUT
10µF
C1
10µF
R1
16.8kΩ
R2
10kΩ
04472-032
Figure 30. 3.3 V DC-to-DC Converter